The present invention relates generally to electric heaters, and more particularly to an improved support and electrical insulation mechanism for the heating coils of an electrical resistance heater.
In the prior art, several different mechanisms have been proposed for the support and electrical insulation of the heater coils of an electrical resistance heater. These prior art mechanisms typically have involved the use of a plurality of non-electrically conductive coil support insulators, such as maybe made for example of a ceramic material. Typically, the prior art coil support insulators have necessitated means for engaging and holding convolutions of the heating coil, and also have required means for holding a plurality of such coil support insulators in spaced array to support one or more heating coils over the extent of their respective lengths.
One form of prior art heating coil support mechanism is set forth in U.S. Pat. No. 4,692,599, and as reexamined B1 4,629,599, wherein a plurality of coil support insulators are held in spaced array by a pair of rods which engage grooves in the sides of the coil support insulator, and which rods are bent into a channel-shape to encircle the insulator by extending along and across its front and back faces.
Another form of coil support insulator is set forth in U.S. Pat. No. 3,798,417, which shows a generally flat coil support element containing an aperture therethrough, through which a serrated support rod is disposed, and which support rod is held in place by a V-shaped clip disposed laterally around a side and both faces of the coil support insulator.
Another form of coil support mechanism is taught in U.S. Pat. No. 4,250,399, wherein a plurality of generally flat-bodied coil support insulators are disposed from transversely extending clips, which in turn are held in position by externally disposed rods.
In addition to the above examples of coil support insulator mechanisms, the prior art teaches a wide variety of other forms of coil support and insulator structures, some of which function more effectively than others. However, notwithstanding the progress of the coil support insulator arts, further improvements have been indicated in regard to the ease, cost and efficiency of production, usability, replaceability versatility, functionality, reliability, inter alia, of these prior arts systems.
In view of the defects, deficiencies and/or disabilities of the prior art coil support insulator structures, it is a material object of the improved heating coil support and insulation mechanism of the present invention to alleviate substantially such prior art problems.
It is a further object of the present invention to provide a coil support structure which generally includes a pair of support rods having at least one locking projection extending from one longitudinal surface of one of said support rods, and respectively inserted into a pair of support rod apertures in the insulator body, and upon twisting of the rod with the projection thereon for locking the support rod and the insulator body into a substantially fixed longitudinal relationship.
It is another object of the improved heating coil support and insulation mechanism of the present invention to provide a coil support structure which includes a pair of support rods having projections for positioning on either side of the support rod apertures in the insulator body for locking the support rod and the insulator body into a substantially fixed longitudinal relationship.
It is a further object of the improved heating coil support and insulation mechanism of the present invention to provide for the versatility of a field replacable coil support insulator, whereby upon damage to a support insulator, a replacement insulator could be merely "twisted" into functional position, without the necessity for insertion of the support rod into a support rod aperture by means of respective longitudinal motion therebetween, and whereby such field repairability is materially enhanced, and further without the necessity for removing the entire module comprising a multiplicity of coils with their associated support structures from the electrical resistance heater.
These and other objects and advantages of the improved heating coil support and insulation mechanism of the present invention will become apparent to those skilled in the art upon review of the following summary of the invention, brief description of the drawing, detailed description of preferred embodiments, appended claims, and accompanying drawings.